Method of making condensers



Dec. 6, 1932. c A1 E 1,890,313

METHOD OF MAKING CONDENSERS Filed Aug. 14, 1931 c j 3 4 9- v 2 Patented Dec. 6, 1932 UNITED STATES PATENT OFFICE CHARLES E. CAINE, O! CHICAGO, ILLINOIS, ASSIGNOB TO TUNG-SOL CONDENSEBS INC OF CHICAGO,

ILLINOIS, CORPORATION OF ILLINOIS mnon O1 MAKING CONDENSEBS Application filed August 14, 1881. Serial No. 556,960.

This invention relates to the method of making condensers.

In my. copending application, Serial No. 526,225, filed March 30, 1931, I disclose a fixed condenser suitable for use as a by-pass condenser, and composed of a section of-tubing in which a condenser unit is encased and held by cup-like end plates pressed into the ends of the tube and against the ends of the con denser unit. My present invention relates to an improved method of constructing condensers of this type.

In the preferred embodiment of my invention the condenser units are formed by winding alternate layers of insulation, preferably paper, and metallic foils into a cylindrical roll from one end of which one of the foils projects and from the other end of which the other foil projects. This type of condenser will be recognized as the so-called non-inductive. type of condenser.

The unit thus formed is thoroughly dehydrated in any convenient manner, preferably by a vacuum treatment, after which an impregnating wax is applied to the unit under pressure. Preferably the wax used for this impregnation has a relatively high melting point.

After the units have been impregnated they are allowed to cool down to room temperature and are then re-impregnated with oil which is heated to a temperature above the melting point of the wax with which they are impregnated. 'The units are allowed to cooldown to room temperature before being removed from the oil and are then drained to remove the excess oil.

The tubes in which the units are to be encased are cut to length and the units placed in them and the end caps also placed in them prior to any special treatment of the tubes themselves. The tubes, being fibrous in nature, will have a moisture content the same as the humidity of the air at the time.

After the unit has thus been completely assembled it is again subjected to vacuum treatment to dehydrate the tubes and to withdraw any air which may have been encased in them durin the assembly of the condenser. After dehy ration has been completed the tubes ably by vacuumtreatment, after impregnated with a suitable wax-likecom- 95 are then impregnated with a suitable impregnating wax, preferably one having a melting point several degrees lower than the melting point with which the condenser unit itself is lmpregnated. This wax fills the voids within the tube and saturates the tube, to thereby. form a perfect seal, protecting the condenser unit from the atmosphere.

After this impregnation has been completed the units are immersed in hot oil to remove any excess wax which may adhere to the outside of them.

My invention will be best understood by reference to the accompanying drawing, in which the steps of it are diagrammatically illustrated and in which:

Figure 1 is a perspective view of the impregnated condenser roll;

Fi 1e 2 is a cross-sectional view of the tube with the condenser unit and caps in place in it prior to final assembly;

Figure 3 is a similar view of the complete? ly assembled condenser unit prior to impregnation; and

Figure 4 is a cross-sectional view of the completely assembled and impregnated condenser unit.

Referring now to the drawing in more detail, the condenser unit consists of a cylindrical roll composed of insulatin members 1 and metallic foils 2 and 3. Pre erably, the insulating members are thin sheets of paper and a plurality of such sheets are used between the foils 2 and 3 to build up suflicient thickness to withstand the electrical 35 stresses for which the condenser unit is designed. As will 'be seen in Figure 1, the foil 2 projects fromone end of the cylindricalbody v the opposite end and the foil 3 projects from ofit.

After the condenser unit 6 has been thus formed, it is thoroughly dehydrated, preferwhich it is pound such asthe chlorinated naphthalene product commercially known as Halowax. Preferably this impregnation is completed under pressure in the usual manner.

Thewax impregnated units are drained and allowed to cool down to room temperature, after which they are immersed in a bath of oil which is at a temperature well above the melting point of the Halowax. This expands the condenser by first melting the wax on the outside of it and subsequently the wax in the interior, and oilis thereby drawn into the-unit to completely saturate it, and to fill any voids that may exist in the wax or insulation or both. The units are allowed to cool down to room temperature before being remowzd from the oil and drained to remove the surplus oil.

,T he foregoing impregnating process is not new, nor is it an indispensable part of the present invention, and it can therefore be varied within the teachings of myjnvention.

The tube 4 in which the condenser unit is encased by metallic/caps 5 is preferably a -per. I have found that paper tubes, commercially available under the trade name of Kraft tubes are adaptable for this purpose. The tubes are cut to length as received from the tube mill, that is, they are not specially treated at this time and therefore contain all the moisture that it is possible for them to absorb from the surrounding air.

The condenser unit 6 is placed in thetube and the caps 5 moved longitudinally of it .under considerable pressure to firmly press them against the ends of the condenser in the manner shown in Figure 3, this operation wadding or matting the projecting ends 2 and 3 of the foils into good electrical contact with the'inside surface of the end caps 5 to thereby establish an electrical connection between the two. This endwise pressing of the condenser unit 6 may form voids indicated at 7 in Figure 3 between its outside surface and the inside surface of the tube. The voids 7 in Figure 3 are, of course, exaggerated to emphasize them.

The unitthus formed is now subjected to vacuum treatment which withdraws moisture from the'tube 4 and withdraws air from the voids 7. After this dehydration has been completed the tube is impregnated with a suitable wax which fills the voids 7 in the manner shown at 8 in Figure 4 and also fills any voi'ds which may be present between the caps 5 and tube 4, as indicated at 9.

Preferably the wax-used in this latter impregnation has a melting pointconsiderably below the melting point of thewax with which the condenser unit 6 is impregnated, so

that the impregnation; f the tube will not materially disturb theimpregnation of the condenser unit itself. I find that with chlorinated naphthalene, commercially known as I-Ialowax used as a substance for impregnatmg the condenser; unit 6, a wax having a meltlng point some 60 below the melting point of Halowax is satisfactory for use to.

impregnate "the tube 4. Obviously other imfibrous tube composed either of fibre or pa-' sealed within the tubes and capable of withstanding severe atmospheric conditions without being deteriorated because of the absorp-- tion of moisture. The process is inexpensive and results in the production of high-grade condensers at low cost.

,While I have chosen to illustrate my in-v vention by describing a preferred embodiment of it, I have done so by way of example only, as there. are many modifications and ada tation which in t e art within tion. v

, WVhat I consider new and desire to have protected by Letters Patent is pointed out in the appended claims.

What is claimed is:

1. The method of impregnatin ing a condenser unit housed in a fibrous casing which comprises, impregnating the condenser unit prior to its assembly in the casing and impregnating the casing after assembly is completed. 1

2. The method of impregnatin and sealing a condenser unit housed in a brous casing which comprises, impregnating and oil treating the unit before'assembly in the casing, vacuum treating the casing and unit after assembly to remove moisture and entrained air, and impregnating the casing to fill the voids in it and to seal the condenser therein.

3. The method of impregnating a condenser composed of a condenser unit encased in a fibrous tubing by contact plates pressed in the ends of the'tube against the ends of the unit which comprises, impregnating the can be made by one skilled the teachings of my invenunit with a wax having a high melting point prior to assembling it in the tube and impregnating the tube and unit in a wax having allowar melting point, after assembly is comp ete 4. The method of impregnating a condenser composed of a condenser u-nit encased ina fibrous tubing by contact plates pressed in the ends of the tube against the ends of the unit which comprises, impregnating the unit with a wax having a high melting point prior to assembling it in the tube and impregnating the tube and unit in a wax having a melting point 40 to 60 degrees below the melting point of the waxwith which the unit is impregnated, after assembly is completed.

and seal-v unit which comprises,

ea ers 5. The method of im regnating a con denser composed of a con enser unit encased in a fibrous tubing by contact plates pressed in the ends of the tube against the ends of the unit which comprises, dehydrating the unit in a vacuum, impregnating the unit under ressure with a wax having a definite melting point, allowing the unit to cool, immersing the cool unit in hot oil and allowing the oil to cool, removing and draining the unit, assembling the unit in a tube, dehydrating the tube, impregnating the tube with wax heated to a temperature below the melting point of the wax with which the unit is imregnated, and immersing the unit and tube in hot oil to remove the surplus wax.

6. The method of impregnating a condenser composed of a condenser unit encased in a fibrous tubing by contact plates pressed in the ends of the tube against the ends of the dehydrating the unit in a vacuum, impregnating the unit under pressure with a wax havlng a definite melting point, allowing the unit to cool, immersing the cool unit in hot oil and allowing the oil to cool, removing and draining the unit, assembling the unit in a tube, subjecting the tube to vacuum to draw out the moisture contained in it and the air encased in it, subjectin the tubeto wax under pressure to fill'the voids within it and to im regnate it, and immersing the tube in hot 011 to remove surplus wax.

7. The method of making a condenser which comprises, rolling alternate layers of insulation and foil into a cylinder from the ends of which a foil projects, dehydrating the roll in vacuum, impregnating the roll with hot wax under pressure, allowing the roll to cool, submerging the cool roll inhot oil, allowin the oil and roll to cool, removing and metallic cups in place a ainst the condenser, dehydrating the tube an condenser, immersing the tube and condenser in hot wax to 1mpregnate the tube and to fill voids in it with wax, and cleanin ofi the surplus wax by immersing the tube in hot oil.

In witness whereof, I hereunto subscribe my name this 11th day of Augilst, 1931.

CHARLES H. CAINE'.

draimn the-roll, cutting a tube of fibrous materia into lengths, placing the roll in a tube length, forming metallic cups to a diameter slightly greater than the diameter of the tube, forcing a'pair of said cups into the tube against the ends of said roll. subjecting the tube to vacuum to withdraw the moisture and entrained air from it, impregnating the tube' with wax to fill the voids in it and to seal it against the entrance of moisture, and dipping the tube in hot oil to remove the surplus wax.

8.- In a condenser in whicha roll of alternately di osed insulation and foils is sealed in a tube y metal cups which serve also as terminals for the foils, the rocess of manu facture which comprises, orming the condenser unit by rolling alternate layers of foil and insulation, debvdrating the condenser impregnating the condenser with hot wax, allowing the condenser to cool, immersin the condenser in hot oil, cutting suitable tu ing to length, placing the impregnated condenser in the tube length, pressing the 

